Knife switch



April 7, 1931- H. J. HAMMERLY 1,799,625l

KNIFE SWITCH Filed May 3, 1929 2 Sheets-Sheet l Figl- April 7, 1931. H. J, HAMMERLY KNIFE SWITCH Filed May 3, 1929 2 Sheets-Sheet 2 xNvENToR Herman f timmer] Patented pr. 7, 1931 wenn mnnnnnni. ELECTRIC MANUFACTURING @tltlPtBMTION F CONNECTICUT comme, or PLAINvrLLE, coimnoricnr,

imma smsen Application ala may a,

This invention applies to electric switches the lnnii'e blade type having pivotally mounted blades which are usually enclosed andwliicli are actuated by' an external handle having an internal crank portion to which portion the blades are connected.

in sach construction '1t is desirable that, the blades be connected to the crank portion oi the operating member by means oi individnal insulating connectors so that the y nlades have no direct connection with each y other their :free ends.

in ity it is desirable to use the indi i 'vic-ical type oiinsulating connectors but in fie E some instances it has been. found desirable to also connector tie the'free ends of the blades to each otherin order to secure and to maint tain alignment' and accuracy in their relative cross bars are nsed, the construction is alf lateral spacing llor the reason that the blades oi enclosed lmaite switches are necessarily made as short @iti as possible, it would be impractical to attach a connecting cross bar of any prior known torni to the ends of the sides of the blades in addition to the individual insulating crank connectors and such construction would not only be prohibitively expensive but it would also be a cumbersome and unganly construction which would conceal the switch contacts, toa considerable extent and thus prevent the necessary visibility of theblades and contacts Awhile the switch is being operated for incrankec'onnector and also a tie bar for conspectioin l ,l

One oi; the objects of my invention is to provide a knife switch construction in which each blade is provided with an individual Serial No. BGOJE.,

in position entirely without the use ci screws, nuts or rivets.

Another object is to provide a tie bar oi such comparatively small dimensions that it will not obstruct the view oi the switch blades or other' parts to any objectionable extent.

Another obj ect is to provide a tie bar which may be secured to the respective blades without cutting away any of the current carrying portion ci the blad-es and without' requiring the use oi special die stamped blade.

ln the preceding paragraphs l have reu erred to my blade connecting' member as a tie bar97 in order to clearly distinguish it from generally lrnown forms ci cross bars., r

.ln prior lswitch constructions in which most invariably such that the cross bar must receive the operating impact andA strains ot the switch but in my present construction, the tie har merely functions to positively position the switch blades laterally and it is entirely relieved from any operating stress or strains whatever and, further, by reason oi not being subject to the usual operating strain, the bar may be much smaller in cross sectional dimensions and therefore much less expensive The general construction of a switch and enclosing box in which my invention may be used may be, for instance, similar to that disclosed in my co-pending application Sera No. 385,250, led January 26, 1929, and may or may not include a quick-break mechanism andthe members vfor connecting the blades and the operating crank may be, for instance, similar to those disclosed in my co-pending application Ser. No. 335,891 filed J an. 29, 1929. e f

` According to my improvement the various switch blades are independently connected with an operating crank by means of. insulating plates or connectors and these plates and the blades are connected together by means of a tie rod which is separate and inde'.-

- pendent of the crank. This tie rod may be connected to the plates and blades in various .ways as shown in the accompanying drawa single knife switch unit in closed circuit position.

Fig. 4 is similar to Fig. 3 but with the blade raised or in open circuit position.

Figs. 5, 6, and 7are detail sectional views of these different forms of connection between the tie bar and the blade and connector.

Fig. 8 shows a pairof blades connected by another form of tie bar.

Fig. 9 is a perspective view of parts of the tie bar of Fig. 8.

The invention is shown and described with reference to an enclosed switch having a box 10 of any suitable type.l The parts of the switch proper are mounted on an insulating base 11 and may include any number of switch units each of which has a lower terminal 12, an upper terminal13 and will usually have fuse clips such as 14 and 15 for any suitable type of fuse. Each switch unit includesa stationary hinge post 16 and the usual spring contact jaws 17 together with a blade 18 which is hinged in this case to the lower stationary post 16.

An insulating plate 19 preferably formed of ibre or similar material is riveted or otherwise secured to each blade and adapted for connection to an operating crank 20. This,

crank may be pivotally supported in the walls of the box or otherwise in any suitable manner. vided with a notch 21 to receive the cross bar of the operating crank.

The switch is adapted to be operated by an external handle 22 and may have any suitable form of quick makeand break mechanism 23 interposed between the handle and the operating crank.

Each-ef the plates 19 is preferably extended beyond the blade and has a foot portion 24 serving asan abutment member to engage the base in the circuit closing movement. This non-metallic plate thus serves as a shock absorber to take up the impact of the switch mechanism and prevents breaking or chipping the base and injury to the metallic parts. The various connector plates 19 are tied together laterally by meansof a bar 25 also preferably `formed of insulating material.

This 'bar may be connected to the blades and plates in various ways. In the preferred form each plate19 is provided `with a transverse opening 26 which is'large enough to receive the tie bar 25 and the tie bar is provided In the form shown each plate isV pro-1 of the opening 26 and has arms which press against the tie bar to hold the tie bar interlocked with. one edge of the switch blade as shown in Fig. 2. It ywill thus be seen that the switch blades are held at their proper distances apart so that even if one switch blade should become loose with respect to its hinge pin or pivot it will nevertheless be maintained in its proper relative position for engagement with its cooperating switch jaw.

The `tie bar being readily insertable and removable, it is possible to disconnect the bar and replace or repair one of the switch blades if necessary, and then replace the bar.

In the form of connection shown in Fig. 5 the hole 26'in the connector plate 19 is filled by supplemental filler strip 30 which is passed through after the tie bar is inserted and may conveniently-be secured in place, for instance, by means of a cotter pin 31.

Iny the form shown in Fig. 6 a clip 33 is inserted in the opening 26 after the tie bar is placed in position and fis then clamped or In the formshown in Fig. 7 the tie bar is inserted into the opening 26 'in the connector plate and the kswitch blade 18 is then inserted in the notch 27 in the tie-bar and the connector 19 is then secured to the blade, for instance, by means of one or more rivets 35.

In the form shown in Fig. 8 the tie bar is made up of sections 37. These may be secured to one plate 19 by means of an anchor piece 38 which extends through the connector 19 and through the blade 18 and is held in place by a rivet 39. Two adj acentsections of the tie bar may be secured together by an anchorage or tie plate 40 which extends through one of the connectors 19 and the corresponding switch plate 18 and is held by rivets such as 41. I,

Among the. .advantages of my invention are that, while it functions perfectly .to accurately space the respective switch blades,`

blades are mounted on the base and without y the use of tools or machinery and it entirely eliminates the use of screws, nuts or rivets- -it is entirely relieved from an operating stress or strains and it may be included in the switch construction without cutting away any ofthe current carrying portion of the blades. Such a tie bar construction can be readily ap- Cir insects plied to existing constructions. lt is also adapted to convenient repair and replacement.

lt should be understood that various other methods of connection between the connector plates 19 and the switch plates 18 may be provided within the spirit and scope of my invention.

l claim:

l. In a knife switch an insulating base, a plurality of switch blades mounted thereon, an insulating connector plate secured to each blade, an operating crank connected with all of said connector plates and a separate tie bar interlocking with and laterallyJ spacing all of said blades independently of said crank.

2. In a knife switch, an insulating base, a number of hinged blades mounted on said base, an insulating connector plate secured to each blade, an operating crank independently coacting with said connector plates and a readily removable tie bar for connecting and laterally spacing all of said blades.

3. In a knife switch an insulating base, a plurality of yhinged blades mounted on'said base, an insulating connector platey secured to each blade, an operating crank connected with all of said connector plates and a separate readily removable tie bar connecting and laterally spacing all of said blades and connector plates..

l. A knife switch construction including an insulating base, a plurality of hinged blades separately mounted on said, base, an insulating connector plate secured to each of said blades and having an extended portion to abut agai st said base to forni a stop for said blades wrlien in the ON position, an operating crank having connection with all of said connector plates and a separate tie bar interlocking with each of said blades and laterally spacing the respective blades and connector plates.

5. ln knife switch, an insulating base, a number of blades mounted on said base, an insulating connector plate secured to each blade, an operating crank coacting with all of said connector plates and a separate tie bar detachably connecting and positively spacl ing all of said blades and the respective plates.

6. ln a/knile switch, an insulating base, a number of blades mounted on said base, a connector plate secured to each blade, an operating crank having operable connection with all of said connector plates, a tie rod passing through said plates and interlocking with said blades for connecting and laterally spacing said blades and means lor clamping said rod in position.

'l'. ln a knife switch', an insulating base, au number of blades mounted on said base, a connector plate secured to each blade, an operating crank coacting with all of said ccnnector plates, a tic rod passing through said plates for connecting the same and a spring member for detachably clamping said rod to said plates.

8. ln a knife switch, a plurality of switch blades, an insulating connector plate secured to each blade, an operating crank coacting with all of said connector plates, a tic rod passing through saidplates for connecting the same and a detachable spring secured to each of said plates and adapted to engage said rod to yieldingly hold the rod in position.

9. In a switch, a p urality of switch units, each consisting of a in ed blade and an insulating connectorv rigid y secured thereto, a notched tie bar connecting all of the switch 4units and spacing them at V4fixed distances from each other and an operating crank coacting with said connectors.

HERMAN JOHN HAMMERLY. l 

